The present invention relates to a two-cycle engine, especially in a manually-guided implement such as a power chain saw, a brush cutter, a trimmer, or the like.
EP 1 176 296 A1 discloses a two-cycle engine, the transfer channels of which are in connection with an air channel via a piston window in prescribed positions of the piston. By means of the air channel and the piston window, largely fuel-free air is supplied to the transfer channels. The air separates the exhaust gases, which in the region of the lower dead center position flow out of the combustion chamber, from the fuel/air mixture, which passes from the crankcase into the combustion chamber. Due to the geometrical configuration of the piston window and of the transfer window, with such two-cycle engines generally no optimum distribution of the air to the transfer channels can be achieved, so that less fuel-free air can be supplied to one of the transfer channels than to the other, as a result of which the fuel/air mixture that subsequently flows into this transfer channel is partially carried-away with exhaust gases through the outlet. A clean separation of exhaust gases and fuel/air mixture cannot be achieved with such a known configuration.
It is therefore an object of the present invention to provide a two-cycle engine of the aforementioned general type whereby a good separation of exhaust gases and subsequently flowing-in fuel/air mixture can be achieved.